Simplifying Cyborg Circuitry Using Human Blood

Could components made from human blood lead to more seamless interfaces between living tissue and electronics?

Researchers are exploring an unconventional approach to bridging biology and electronics: using human blood to form electronic components. A team in India reports that blood can exhibit memristor behavior, a property long theorized and only recently harnessed in solid-state devices. If developed further, blood-based components could help form more natural, efficient links between neural tissue and electronic devices such as prosthetic limbs, retinal implants, or other cyborg interfaces.

A memristor is a two-terminal passive device whose resistance changes according to the history of voltage and current applied to it, effectively retaining a memory of past electrical activity. The concept was first proposed in 1971 by electrical engineer Leon Chua and later realized in laboratory devices by researchers at Hewlett-Packard using titanium dioxide in 2008. Memristors are of interest for their applications in non-volatile memory, neuromorphic computing, programmable logic, signal processing, and artificial neural networks because their state-dependent conductance can emulate synaptic behavior.

In their study published in the International Journal of Medical Engineering and Informatics, S.P. Kosta and colleagues at the Education Campus Changa in Gujarat describe constructing a simple biological memristor from human blood. Their laboratory device consisted of a 10 ml test tube maintained at 37 °C containing human blood, into which two electrodes were inserted and connected to measurement equipment. Under controlled conditions the blood displayed a clear dependence of resistance on both the polarity and magnitude of applied voltage, and it retained this altered resistance state for several minutes — demonstrating a measurable memory effect.

To test whether this behavior persisted under more realistic conditions, the researchers next created a flowing version of the device where blood moved through a channel while measurements were taken. This dynamic setup also demonstrated memristive behavior. Building on these results, the team plans to miniaturize the design into microchannel devices and to combine multiple flow memristors to implement basic logic or processing functions. Those steps aim to move from a laboratory curiosity toward practical components that might integrate with living tissues.

While this work is preliminary and far from creating direct electronic-biological interfaces in humans, it highlights several important possibilities. Using biological fluids or tissues as part of electronic circuits could reduce mechanical and chemical mismatches at the interface between artificial devices and living cells. A circuit element that mimics the adaptive, history-dependent behavior of synapses may be especially useful for prosthetics and neural interfaces, where smooth, bidirectional communication between electronics and nerve cells is essential.

There remain significant technical and ethical challenges. Long-term stability, biocompatibility, sterility, safety, and reliable control of electrical properties in complex biological media must be demonstrated before any clinical application can be considered. Scaling laboratory demonstrations into microfabricated, reproducible devices that operate safely in or near living tissue will require multidisciplinary advances in materials science, microfluidics, bioelectronics and regulatory guidance.

Nevertheless, the demonstration that human blood can behave as a memristive material adds an intriguing option to the toolbox of bioelectronics. Future work that refines microchannel designs, integrates multiple elements for logic and memory, and tests interactions with neural cells could help determine whether blood-derived components offer practical advantages for building more natural, adaptive cyborg interfaces.

Notes about this research article

Contact: S P Kosta
Source: Inderscience Publishers
Image Source: Image adapted from Flickr image by mize2005 and Wikimedia image by MDougM.
Journal Source: “Human blood liquid memristor” in International Journal of Medical Engineering and Informatics, 2011, 3, 16-29